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DR. KATHLEEN WALKER MAYER MD
NPI 1457488439
Internal Medicine in Bakersfield, CA

Active since February 27, 2007PECOS Enrolled
4900 CALIFORNIA AVE FL 2, BAKERSFIELD, CA 93309(617) 505-1520(617) 928-8401 Get Directions Write a Review

NPPES record last updated: June 11, 2026. Verified against the NPPES registry weekly; last sync: August 09, 2026.

Record update history: Mar 14, 2025, Feb 11, 2025, Oct 6, 2021 and 1 more (4 updates tracked since 2020).

About Dr. Kathleen Walker Mayer Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. KATHLEEN WALKER MAYER MD (NPI 1457488439) is an individual internal medicine provider in Bakersfield, California, licensed in California (C176095) and active in the NPI registry since February 2007. She is enrolled in Medicare PECOS and is a graduate of University Of Colorado School Of Medicine, Denver (1997).

NPPES Registry Identity

NPI1457488439
Entity TypeIndividualFemale
Primary Taxonomy207R00000X
Provider Legal NameDR. KATHLEEN WALKER MAYERCredential: MD
Location Address4900 CALIFORNIA AVE FL 2Bakersfield, CA 93309-7024
Mailing Address109 S State St Ste 5Chicago, IL 60603-5606 · (617) 505-1520 · Fax (617) 928-8401
Phone(617) 505-1520
Fax(617) 928-8401
Sole ProprietorNo
Medical School CMSUniversity Of Colorado School Of Medicine, DenverGraduated 1997
Enumeration DateFebruary 27, 2007
Last NPPES UpdateJune 11, 20264 updates tracked since enumeration
NPPES CertifiedJune 11, 2026
✔ NPI 1457488439 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
Licenses✔ Licensed in CA · C176095✔ Licensed in CO · 37902
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
4900 CALIFORNIA AVE FL 2, Bakersfield, CA 93309
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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Kathleen Walker Mayer Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

PECOS PAC ID1759465198
PECOS Enrollment IDI20260212000184
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 93309 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$135.05 typical visit price
range $59.26 – $178.09
Typical copayment $33.76 (range $14.81 – $44.52)
Most-billed visit code 99204
Established Patient
$104.09 typical visit price
range $19.34 – $145.64
Typical copayment $26.02 (range $4.83 – $36.41)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Referred Medical Equipment & Supplies CMS DME claims 2

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Portable gaseous oxygen system, rental; includes portable container, regulator, flowmeter, humidifier, cannula or mask, and tubing E0431
DME-Oxygen and Supplies · category DC000N
1 supplier12 claims12 services$11.46 avg. paid by Medicare
Oxygen concentrator, single delivery port, capable of delivering 85 percent or greater oxygen concentration at the prescribed flow rate E1390
DME-Oxygen and Supplies · category DC002N
1 supplier12 claims12 services$57.10 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 5

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

MELANIE JOY MADRIAGA DO
Family Medicine
4900 CALIFORNIA AVE FL 2, TOWER B, 2ND FLOOR
BAKERSFIELD, CA 93309
Kern County (617) 505-1520
DR. NIYOTI REDDY M.D.
Internal Medicine (Endocrinology, Diabetes & Metabolism)
4900 CALIFORNIA AVE FL 2
BAKERSFIELD, CA 93309
Kern County (617) 505-1520
MY VIRTUAL PHYSICIAN PC
Family Medicine
4900 CALIFORNIA AVE FL 2
BAKERSFIELD, CA 93309
Kern County (888) 224-0804
LISA MARIE GAUSE FNP-BC
Nurse Practitioner (Family)
4900 CALIFORNIA AVE FL 2
BAKERSFIELD, CA 93309
Kern County (617) 505-1520
MNZ CORPORATION
Durable Medical Equipment & Medical Supplies
4900 CALIFORNIA AVE FL 2
BAKERSFIELD, CA 93309
Kern County (818) 268-8186

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Kathleen Mayer's NPI number?

The NPI number for Kathleen Mayer is 1457488439. It was assigned to this individual provider in the NPPES registry on February 27, 2007.

Where is Kathleen Mayer located?

Kathleen Mayer practices at 4900 California Ave Fl 2, Bakersfield, CA 93309. The listed phone number is (617) 505-1520.

What is Kathleen Mayer's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Kathleen Mayer enrolled in Medicare?

Yes. Kathleen Mayer is registered in the Medicare PECOS enrollment system.

When was this NPI record last updated?

The NPPES record for Kathleen Mayer was last updated on June 11, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.